SKALARSan++连续流动分析仪测定水中阴离子表面活性剂

目的建立SKALARSan++连续流动分析仪测定水中的阴离子表面活性剂的方法。方法澄清水样直接取样,污水、废水需过滤或者超声前处理,用SKALARSan++连续流动分析仪测定水中阴离子表面活性剂的含量。结果在浓度为(0.050~0.500)mg/L范围内,线性关系良好,相关系数达到0.999 1;最低检出限为4.1μg/L;目标物的加标回收率为95%~110%;精密度RSD小于6%。对水质阴离子表面活性剂标样进行分析,测定结果在标准值参考范围内。结论此方法可用于水中阴离子表面活性剂的含量测定,具有操作简单、分析速度快、试剂消耗少、准确度高、对操作人员危害小等特点,且能满足大批量样品的快速分析,对使用Skalar San++连续流动分析仪测定水体中阴离子表面活性剂所出现的问题加以说明并进行了探讨。     

苋菜红两相滴定法测定水中阴离子表面活性剂

本文首次提出以苋菜红为指示剂,用两相滴定法测定水中阴离子表面活性剂的方法。用此法测定了环境水样中的阴离子表面活性剂,相对标准差为0.65％～6.5％,回收率为94％～105％,检测下限为50μg/L。方法简便,快速,具有良好的选择性,适用于河水和生活废水中阴离子表面活性剂的测定。     

SKALARSan++连续流动分析仪测定水中阴离子表面活性剂

目的建立SKALARSan++连续流动分析仪测定水中的阴离子表面活性剂的方法。方法澄清水样直接取样,污水、废水需过滤或者超声前处理,用SKALARSan++连续流动分析仪测定水中阴离子表面活性剂的含量。结果在浓度为(0.050~0.500)mg/L范围内,线性关系良好,相关系数达到0.999 1;最低检出限为4.1μg/L;目标物的加标回收率为95%~110%;精密度RSD小于6%。对水质阴离子表面活性剂标样进行分析,测定结果在标准值参考范围内。结论此方法可用于水中阴离子表面活性剂的含量测定,具有操作简单、分析速度快、试剂消耗少、准确度高、对操作人员危害小等特点,且能满足大批量样品的快速分析,对使用Skalar San++连续流动分析仪测定水体中阴离子表面活性剂所出现的问题加以说明并进行了探讨。     

健那绿共振光散射法测定水中阴离子表面活性剂

〔目的〕建立一种简便快速的环境水样中阴离子表面活性剂 (AS)测定新方法。〔方法〕健那绿 (JG)共振光散射水相直接测定法。〔结果〕研究了含吩嗪结构类染料JG与十二烷基苯磺酸钠 (SDBS)作用的共振光散射光谱 ,在pH12 2～ 12 6的范围内 ,加入SDBS导致JG共振光散射剧烈增强 ,在λex=λem =62 5nm处 ,存在一共振光散射峰 ,其强度与SDBS的浓度成线性关系 ,据此建立了一种测定水中AS的共振光散射法。方法的线性范围为 0～ 3 4 8μ犂 10ml,检出限为17 8ng ml。〔结论〕方法简便、快速 ,可直接测定环境水样中的阴离子表面活性剂。     

海水中阴离子表面活性剂的萃取-分光光度法测定

为提高阴离子表面活性剂测定的灵敏度,简化操作步骤,作者详细研究了乙基紫-甲苯萃取法,建立了定量海水中阴离子表面活性剂的测定方法,以十二烷基硫酸钠为例,可一次萃取完全。本法表观摩尔吸光系数为92500,标准曲线在0～2.0×10~(-5)M的浓度范围内呈良好的线性。大量共存的氯离子的干扰可采用0.08 M盐酸洗有机相加以除去。共存海水中的其它主要离子和硼酸对测定无干扰。海水中10 ppb～0.3 ppm的阴离子表面活性剂能准确地进行定量。方法回收率为91～99%。主要试剂和仪器: 8.8×10~(-3)M乙基紫溶液,十二烷基硫酸钠(SLS)溶液,0.5 M醋酸-醋酸钠缓冲溶     

阴离子表面活性剂的龙胆紫褪色光度测定法

在弱酸性的邻苯二甲酸氢钾-HCl缓冲介质中,阴离子表面活性剂(AS)与龙胆紫(CV)染料反应,形成离子缔合物,溶液颜色发生明显改变。最大褪色波长为578 nm[十二烷基硫酸钠(SDS)体系]、574 nm[十二烷基苯磺酸钠(SDBS)体系],在此波长处,阴离子表面活性剂的浓度与体系吸光度呈良好线性关系,从而建立测定阴离子表面活性剂的光度法。在最大褪色波长处,AS的浓度在0~2.79×10-5mol/L(SDS体系)、0~2.90×10-5mol/L(SDBS体系)范围内遵守比耳定律,表现摩尔吸光系数为1.72×104L/(mol.cm)(SDS体系)、1.86×104L/(mol.cm)(SDBS体系),检出限为8.90×10-7mol/L(SDS体系)、7.81×10-7mol/L(SDBS体系)。该方法具有较高的灵敏度和良好的选择性,用于水样中AS的测定,结果满意。     

Cd(Ⅱ)-碘化钾-结晶紫-OP10反应的分光光度研究及应用

〔目的〕为研究灵敏而简便的环境水样中痕量镉测定技术。〔方法〕在表面活性剂OP -10存在下 ,镉与结晶紫、碘化钾形成混配缔合物 ,建立了测定水体中痕量镉的光度法。〔结果〕该缔合物的最大吸收波长在 63 5 .9nm ,表观摩尔吸光系数ε为 1.0 4× 10 6 L mol·cm ,回收试验的相对标准偏差为 1.15 % -2 .68% ,回收率为 99.0 % -10 0 .8% ,在 0 -1.0 μgCd/10ml范围内服从比尔定律。〔结论〕该体系是测定镉的超高灵敏度光度法之一。本方法用于环境水样及中镉的测定 ,获得了满意结果。     

3,5-diBr-DMPAP光度法测定全血铁

目的 :建立一种快速、简便、灵敏分光光度法测定全血中微量铁。方法 :在表面活性剂 Tri-ton X-1 0 0存在下 ,用 2 -(3 ,5 -二溴 -2 -吡啶偶氮 ) -5 -二甲氨基酚 (简称 3 ,5 -di Br-DMPAP)作显色剂直接光度法测定全血中微量铁。结果 :该方法在 p H4.0的乙酸 -乙酸钠缓冲液中 ,以 746nm为测定波长 ,可选择性测定全血中微量铁 ,本法线性范围为 0～ 1 0μg/ 3 .4ml,表观摩尔吸光数为 2 .75× 1 0 4 L/ (mol· cm) ,回收率为 98.4%～ 1 0 1 .3 %。结论 :该法具有操作快速、简便、结果灵敏可靠等优点 ,适合临床应用     

5-Br-DMPAP直接光度法测定血清铜

目的 :建立一种快速、简便、灵敏分光光度法测定血清铜 ;方法 :在表面活性剂 Triton X-1 0 0存在下 ,用 2 - ( 5 -溴 - 2 -吡啶偶氮 ) - 5 -二甲氨基酚 (简称 5 - Br- DMPAP)作显色剂直接光度法测定血清铜 ;结果 :该方法测定血清铜 ,显色络合物最大吸收波长为 5 60 nm,线性范围达 63.0 μ mol· L-1,表观摩尔吸光数为 5 .89× 1 0 4 L·mol-1·cm-1。回收率为 98.8%～1 0 1 .5 % ,变异系数 ( CV) 2 .3% ,与原子吸收分光光度法比较相关良好 ,Y=0 .95 5 X+ 0 .833,r=0 .9663,P>0 .0 5 ,36例健康人血清铜含量为 1 0 .0～ 2 3.6μmol· L-1( x± 2 s) ;结论 :该法血清用量少 ,不必去蛋白 ,具有操作快速、简便、结果灵敏可靠等优点 ,适合临床应用     

氯化十六烷基吡啶—百里酚蓝光度法测定水中阴离子表面活性剂

阴离子表面活性剂（ＡＳ）对生态环境和人类健康的影响日益受到人们的关注。而检测环境水样中ＡＳ的亚甲蓝分光光度法需用有毒的有机溶剂多次萃取［１］，易造成环境污染，且操作不便。本文建立了氯化十六烷基吡啶（ＣＰＣ）－百里酚蓝（ＴＢ）分光光度法测定ＡＳ的新方法...     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.